Multilayered golf ball having whiskers and manufacturing method thereof

ABSTRACT

A multilayered golf ball having inside whiskers and a method for manufacturing the same are provided. The method includes the steps of forming a ball core, forming an inner cover layer to cover the ball core, and forming an outer cover layer to cover the inner cover layer. The outer cover layer has a flexural modulus between 20 MPa and 600 MPa and the inner cover layer has a flexural modulus between 20 MPa and 400 MPa. The inner cover layer has a three-dimensional network structure that is formed by the whiskers, and the whiskers are in an amount between 1 wt % and 5 wt % of the total weight of the inner cover layer.

CROSS-REFERENCE TO RELATED PATENT APPLICATION

This application claims the benefit of priority to Taiwan Patent Application No. 108104826, filed on Feb. 13, 2019. The entire content of the above identified application is incorporated herein by reference.

Some references, which may include patents, patent applications and various publications, may be cited and discussed in the description of this disclosure. The citation and/or discussion of such references is provided merely to clarify the description of the present disclosure and is not an admission that any such reference is “prior art” to the disclosure described herein. All references cited and discussed in this specification are incorporated herein by reference in their entireties and to the same extent as if each reference was individually incorporated by reference.

FIELD OF THE DISCLOSURE

The present disclosure relates to a multilayered golf ball, and more particularly to a multilayered golf ball having inside whiskers and a method for manufacturing the same.

BACKGROUND OF THE DISCLOSURE

With the increase of living standards and the emphasis on outdoor recreational activities, more and more people have taken an interest in golf, including men and women from all walks of life or of all ages. That is to say, golf players of different industries, different countries and/or different genders can play together for competition and communication. Such is the appeal of golf.

In a golf event, golfers must continue to drive the golf ball forward, and the carry distance of the golf ball and the controllability of the strokes of the golf ball often become the key points to winning the golf event. Although the outcome of the golf event may depend upon a golfer's skill level, the characteristics of the golf ball also have a degree of influence on success. For example, multilayered golf balls with plural layers of different materials can produce additional features such as an increased initial velocity and an increased or decreased spin rate, such that the flight trajectory and the carry distance can be easily controlled.

Therefore, a technical solution for increasing moving distances of the golf ball and improving the playability of the golf ball has been actively studied based on many years of experience in golf ball design and manufacture.

SUMMARY OF THE DISCLOSURE

In response to the above-referenced technical inadequacies, the present disclosure provides a multilayered golf ball having inside whiskers which can meet the use requirements of professional and amateur golfers.

In one aspect, the present disclosure provides a multilayered golf ball having inside whiskers, including a ball core, an outer cover layer covering the ball core, and at least one inner cover layer disposed between the ball core and the outer cover layer. The outer cover layer has a flexural modulus between 20 MPa and 600 MPa, and the inner cover layer has a flexural modulus between 20 MPa and 400 MPa. The inner cover layer has a three-dimensional network structure that is formed by the whiskers, and the whiskers are in an amount between 1 wt % and 5 wt % of the total weight of the inner cover layer.

In one aspect, the present disclosure provides a method for manufacturing a multilayered golf ball having inside whiskers, including: forming a ball core; forming an inner cover layer to cover the ball core, wherein the inner cover layer has a flexural modulus between 20 MPa and 400 MPa, the inner cover layer has a three-dimensional network structure that is formed by the whiskers, and the whiskers are in an amount between 1 wt % and 5 wt % of the total weight of the inner cover layer; and forming an outer cover layer to cover the inner cover layer, wherein the outer cover layer has a flexural modulus between 20 MPa and 600 MPa.

In certain embodiments, the whiskers are in an amount between 2.5 wt % and 3 wt % of the total weight of the inner cover layer.

In certain embodiments, the whiskers are zinc oxide whiskers.

In certain embodiments, the outer cover layer is formed from a metal cation based low acid ionomer resin, and the inner cover layer is formed from a highly neutralized acid polymer resin.

In certain embodiments, the flexural modulus of the outer cover layer is between 29.6 MPa and 489 MPa, and the flexural modulus of the inner cover layer is between 44.8 MPa and 220 MPa.

In certain embodiments, the ball core has a coefficient of restitution (COR) between 0.65 and 0.85.

In certain embodiments, the step of forming the inner cover layer includes: mixing the whiskers and one molding resin in a weight ratio of 1:9 to form a first resin composition; granulating the first resin composition to form masterbatches; mixing the masterbatches and another one molding resin in a weight ratio of 3:7 to form a second resin composition; and using the second resin composition as a raw material for injection molding.

One of the advantages of the present disclosure is that the multilayered golf ball having inside whiskers and the method for manufacturing the same, which can increase the total distance (i.e., carry distance plus roll distance) while providing a balance between the spin revolution, the stroke feel and the durability of the golf ball by the technical solution as follows: the inner cover layer has a three-dimensional network structure that is formed by the whiskers, the whiskers are in an amount between 1 wt % and 5 wt % of the total weight of the inner cover layer, and the inner and outer cover layers each have a predetermined flexural modulus.

These and other aspects of the present disclosure will become apparent from the following description of the embodiment taken in conjunction with the following drawings and their captions, although variations and modifications therein may be affected without departing from the spirit and scope of the novel concepts of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more fully understood from the following detailed description and accompanying drawings.

FIG. 1 is a flowchart of a method for manufacturing a multilayered golf ball having inside whiskers of the present disclosure.

FIG. 2 is a partial perspective view of the multilayered golf ball having inside whiskers according to a first embodiment of the present disclosure.

FIG. 3 is a sectional view of the multilayered golf ball having inside whiskers according to the first embodiment of the present disclosure.

FIG. 4 is an enlarged view of section IV of FIG. 3.

FIG. 5 is a partial perspective view of the multilayered golf ball having inside whiskers according to a second embodiment of the present disclosure.

FIG. 6 is a sectional view of the multilayered golf ball having inside whiskers according to the second embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

As known to everyone, the performances of golf balls would be affected by respective layered structures and materials thereof Therefore, the present disclosure provides a method for manufacturing a golf ball, which can manufacture a golf ball having any suitable number of layers (e.g., three layers or more). Moreover, the manufactured golf ball can have an increased total distance (i.e., carry distance plus roll distance) without sacrificing the spin revolution, stroke feel and durability of the ball.

The present disclosure is more particularly described in the following examples that are intended as illustrative only since numerous modifications and variations therein will be apparent to those skilled in the art. Like numbers in the drawings indicate like components throughout the views. As used in the description herein and throughout the claims that follow, unless the context clearly dictates otherwise, the meaning of “a”, “an”, and “the” includes plural reference, and the meaning of “in” includes “in” and “on”. Titles or subtitles can be used herein for the convenience of a reader, which shall have no influence on the scope of the present disclosure.

The terms used herein generally have their ordinary meanings in the art. In the case of conflict, the present document, including any definitions given herein, will prevail. The same thing can be expressed in more than one way. Alternative language and synonyms can be used for any term(s) discussed herein, and no special significance is to be placed upon whether a term is elaborated or discussed herein. A recital of one or more synonyms does not exclude the use of other synonyms. The use of examples anywhere in this specification including examples of any terms is illustrative only, and in no way limits the scope and meaning of the present disclosure or of any exemplified term. Likewise, the present disclosure is not limited to various embodiments given herein. Numbering terms such as “first”, “second” or “third” can be used to describe various components, signals or the like, which are for distinguishing one component/signal from another one only, and are not intended to, nor should be construed to impose any substantive limitations on the components, signals or the like.

First Embodiment

Referring to FIG. 1, the first embodiment of the present disclosure provides a method for manufacturing a multilayered golf ball having inside whiskers, including the following steps. The first step (i.e., step S100) is forming a ball core. The next step (i.e., step S102) is forming an inner cover layer to cover the ball core. The last step (i.e., step S104) is forming an outer cover layer to cover the inner cover layer.

Reference is made to FIG. 2 to FIG. 4, the ball core 1 can be formed by any method known in the related art such as injection molding. The ball core 1 has a diameter between 1.40 inches and 1.64 inches. More specifically, the material of the ball core 1 can be injected into a ball mold (not shown) and heated at a suitable temperature for molding. After molding, the ball core 1 is removed from the ball mold and cooled to maintain its shape.

In the present disclosure, the material of the ball core 1 mainly includes a natural or synthetic rubber or a material containing the natural or synthetic rubber (hereinafter “rubber material”). The rubber material is present in an amount between 50% and 70% by weight of the total weight of the ball core 1. The ball core 1 can have desired property(s) by using a suitable rubber material. For example, the ball core 1 is controlled to have a coefficient of restitution (COR) between 0.65 and 0.85. Accordingly, the initial ball velocity after being hit can be increased, such that the carry distance of the golf ball can be increased. In other embodiments, the material of the ball core 1 may be a thermoplastic material such as an ionomer resin, a polyamide resin, a polyester resin, a polyurethane resin, or any combination thereof.

According to actual requirements, the ball core 1 may include one or more additives. The additives may include a crosslinking agent and a filler, but are not limited thereto. Specific examples of the crosslinking agent include zinc acrylate and magnesium acrylate. Specific examples of the filler include zinc oxide, barium sulfate, and a high specific gravity metal powder (e.g., tungsten powder).

In the step S102, the inner cover layer 2 can be formed by any method known in the related art such as injection molding. The inner cover layer 2 has a thickness between 0.01 inches and 0.6 inches. In other embodiments, a compression mold (not shown) can be used to form the material of the inner cover layer 2 into two hemispherical structures (not shown) surrounding the ball core 1. After that, the two hemispherical structures can be melted at a suitable temperature and subsequently combined together in the form of a molten flow, so to form the complete inner cover layer 2.

In the present embodiments, the composition of the inner cover layer 2 includes a highly neutralized acid polymer resin and a plurality of whiskers W. The highly neutralized acid polymer resin can be present in an amount between 95% and 99% by weight of the total weight of the inner cover layer 2. The whiskers W can be present in an amount between 1% and 5% by weight of the total weight of the inner cover layer 2, preferably between 2.5% and 3% by weight, and preferably between 2.8% and 3% by weight. The whiskers W may have the same or different irregular shapes. Each of the whiskers W has an outer diameter between 1 mm and 50 mm and an aspect ratio between 5 and 1000. It should be noted that, the inner cover layer 2 has a flexural modulus between 20 MPa and 400 MPa, preferably between 44.8 MPa and 220 MPa.

The highly neutralized acid polymer resin can be an HPF resin produced by E. I. DuPont de Nemours & Co. Specific examples of the HPF resin include HPF 1000, HPF 2000, HPF AD1035, HPF AD1043 and HPF AD1172 resins. The whiskers W are tetrapod-shaped zinc oxide (ZnO) whiskers. However, the present disclosure is not limited to such examples. In other embodiments, the whiskers W can be at least one of other oxide whiskers, carbide whiskers, nitride whiskers, boride whiskers, and inorganic whiskers.

According to actual requirements, a metal cation source such as a magnesium, sodium, zinc or potassium source can be used to neutralize the acid polymer by 80% or greater. The inner cover layer 2 may include one or more additives. The additives may include a melt flow modifier and a colorant such as a white pigment, but are not limited thereto. Specific examples of the melt flow modifier include fatty acids and their salts, polyamines, polyesters, polyacrylates, polyurethanes, polyethers, polyureas and polyols.

In the present disclosure, a metal cation based low acid ionomer resin can be used in place of the highly neutralized acid polymer resin contained in the inner cover layer 2. The metal cation based low acid ionomer resin can be a Surlyn resin (Surlyn is a registered trademark) produced by E. I. DuPont de Nemours & Co. Specific examples of the SURLYN resin include Surlyn 8150, Surlyn 8320, Surlyn 8940, Surlyn 8945, Surlyn 9120, Surlyn 9150, Surlyn 9320W, Surlyn 9910, Surlyn 9945, Surlyn 9950 and Surlyn AD1022 resins.

It should be noted that, the inner cover layer 2 is prepared by the following steps, so as to disperse the whiskers W. Firstly, whiskers are mixed with one molding resin (e.g., highly neutralized acid polymer resin or metal cation based low acid ionomer resin) in a weight ratio of 1:9 to form a first resin composition. Next, the first resin composition is granulated to form masterbatches. Next, the masterbatches are mixed with another one molding resin (e.g., highly neutralized acid polymer resin) in a weight ratio of 3:7 to form a second resin composition. Lastly, the second resin composition is used as a raw material for injection molding. That is to say, the raw material based on the second resin composition is injected into a compression mold.

Furthermore, the whiskers W contained in the inner cover layer 2 are interlaced to form a three-dimensional network structure 21. In the three-dimensional network structure 21, the comprehensive performance of the golf ball can be increased. For example, the inner cover layer 2 can have a synergistic interaction with the ball core 1 to increase the total distance (i.e., carry distance plus roll distance). Furthermore, the inner cover layer 2 can have a synergistic interaction with the outer cover layer 3 to at least achieve the effects of increasing the spin revolution of the golf ball, improving the stroke feel and increasing the durability.

In the step S104, the outer cover layer 3 can be can be formed by any method known in the related art such as compression molding. The outer cover layer 3 has a thickness between 0.01 inches and 0.2 inches. More specifically, a compression mold (not shown) can be used to form the material of the outer cover layer 3 into two hemispherical structures (not shown) surrounding the ball core 1. After that, the two hemispherical structures can be combined together in the form of a molten flow at a temperature between 50° C. and 200° C., so to form the complete outer cover layer 3.

In the present disclosure, the main material of the outer cover layer 3 can be a metal cation based low acid ionomer resin or polyurethane The main material can be present in an amount between 80% and 100% by weight of the total weight of the outer cover layer 3. The metal cation based low acid ionomer resin can be a Surlyn resin (Surlyn is a registered trademark) produced by E. I. DuPont de Nemours & Co. Specific examples of the SURLYN resin include Surlyn 8150, Surlyn 8320, Surlyn 8940, Surlyn 8945, Surlyn 9120, Surlyn 9150, Surlyn 9320W, Surlyn 9910, Surlyn 9945, Surlyn 9950 and Surlyn AD1022 resins. It should be noted that, the outer cover layer 3 has a flexural modulus between 20 MPa and 600 MPa.

According to actual requirements, the outer cover layer 3 may include one or more additives to enable the golf ball to have desired characteristics such as being aesthetic, practical and durable. Specific examples of the additive include a coloring agent, a matting agent, an ultraviolet absorber, an antioxidant, a hardener, a modifier and a filler.

After completing the above steps, a multilayered golf ball G having inside whiskers W is manufactured. The multilayered golf ball G includes a ball core 1, an outer cover layer 3 covering the ball core 1, and at least one inner cover layer 2 disposed between the ball core 1 and the outer cover layer 3. The at least one inner cover layer 2 has a three-dimensional network structure 21 that is formed by the whiskers W.

Although FIG. 2 and FIG. 3 show that the multilayered golf ball G includes only one inner cover layer 2, according to actual requirements, the step S102 can be repeatedly performed twice or more so as to form a plurality of inner cover layers 2 disposed between the ball core 1 and the outer cover layer 3. For example, a three-layered golf ball needs only one inner cover layer 2, and a four-layered golf ball needs two inner cover layers 2.

Reference is again made to FIG. 2 and FIG. 3, in order to improve aerodynamic characteristics of the golf ball, the surface of the outer cover layer 3 can have a plurality of dimples 31. The dimples 31 can have a shape known in the related art such as a hemispherical shape. The number of the dimples 31 can be 200 to 500, preferably 250 to 400. Without affecting the expected effects of the present disclosure, any type of a coating known in the related art such as a protective coating, a colorant coating or a matting coating may be formed on the surface of the outer cover layer 3.

Second Embodiment

Referring to FIG. 1 along with FIG. 5 and FIG. 6, a second embodiment of the present disclosure provides a multilayered golf ball having inside whiskers and a method for manufacturing the same. The method includes the following steps: step S100, forming a ball core; step S102, forming an inner cover layer to cover the ball core; and step S104, forming an outer cover layer to cover the inner cover layer.

The main difference of the second embodiment from the first embodiment is that the step S100 includes forming an inner ball core 1 a and subsequently forming an outer ball core 1 b to cover the inner ball core 1 a. The inner ball core 1 a and the outer ball core 1 b can each be formed by any method known in the related art. For example, the inner ball core 1 a injection molding and the outer ball core 1 b can be formed by compression molding. Associated details have been described in the first embodiment, and will not be reiterated herein.

In the present embodiment, the inner ball core 1 a and the outer ball core 1 b can be made of a natural or synthetic rubber or a material containing a natural or synthetic rubber, but are not limited thereto. The inner ball core 1 a and the outer ball core 1 b can have different characteristics from each other. For example, the inner ball core 1 a has a lower Shore hardness than the outer ball core 1 b.

Items Under Evaluation

Golf balls of an example and a comparative example are repeatedly hit numerous times by a No. 6 iron club and a driver club (product name “JetSpeed”, purchased from TaylorMade Golf Co Inc.) with a club speed of 110 under the same test conditions (e.g., environmental conditions and club speed and force). The results of carry distances, total distances and spin rates of the golf ball are shown in Table 1 and Table 2.

In addition, twelve golf balls of the example and the comparative example are repeatedly shot at a speed of 175 ft/s by the ADC COR machine developed by Automated Design Corporation to impact a steel board until the golf balls break. The number of times that the first six broken golf balls are submitted to impact are shown in Table 3.

The golf balls of the example and the comparative example are three layered golf balls having a Shore hardness of 62±2 and a compression of 65±7. The difference is that the inner cover layer (i.e., mid layer) of the golf ball of the example contains 3% by weight of whiskers and the inner cover layer (i.e., mid layer) of the golf ball of the example contains no whiskers.

TABLE 1 flight performance test Driver Carry distance Total distance Spin rate (Yard) (Yard) (RPM) Example 260.7 285.7 2772.6 Comparative 260.6 282.2 2875.2 example

TABLE 2 flight performance test 6 Iron Carry distance Total distance Spin rate (Yard) (Yard) (RPM) Example 50.2 55.9 6098.1 Comparative 50.1 56.1 5052.2 example

TABLE 2 impact resistance test Example Comparative example 1 86 63 2 86 76 3 87 78 4 88 78 5 88 84 6 89 84

One of the advantages of the present disclosure is that the multilayered golf ball having inside whiskers and the method for manufacturing the same, which can increase the total distance (i.e., carry distance plus roll distance) while providing a balance between the spin revolution of the golf ball, the stroke feel and the durability by the technical solution as follows: the inner cover layer has a three-dimensional network structure that is formed by the whiskers, the whiskers are in an amount between 1 wt % and 5 wt % of the total weight of the inner cover layer, and the inner and outer cover layers each have a predetermined flexural modulus.

Furthermore, the method of the present disclosure can allow the whiskers in the inner cover layer to be uniformly dispersed so as to avoid the aggregation of the whiskers that may affect the performance of the golf ball by the technical solution as follows: the whiskers are mixed with one molding resin in a weight ratio of 1:9, and a portion of an obtained resin composition is mixed with another one molding resin in a weight ratio of 3:7.

The foregoing description of the exemplary embodiments of the disclosure has been presented only for the purposes of illustration and description and is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Many modifications and variations are possible in light of the above teaching.

The embodiments were chosen and described in order to explain the principles of the disclosure and their practical application so as to enable others skilled in the art to utilize the disclosure and various embodiments and with various modifications as are suited to the particular use contemplated. Alternative embodiments will become apparent to those skilled in the art to which the present disclosure pertains without departing from its spirit and scope. 

What is claimed is:
 1. A multilayered golf ball having inside whiskers comprising a ball core, an outer cover layer covering the ball core, and at least one inner cover layer disposed between the ball core and the outer cover layer, wherein the outer cover layer has a flexural modulus between 20 MPa and 600 MPa and the inner cover layer has a flexural modulus between 20 MPa and 400 MPa, the inner cover layer has a three-dimensional network structure that is formed by the whiskers, and the whiskers are in an amount between 1 wt % and 5 wt % of the total weight of the inner cover layer.
 2. The multilayered golf ball according to claim 1, wherein the whiskers are in an amount between 2.5 wt % and 3 wt % of the total weight of the inner cover layer.
 3. The multilayered golf ball according to claim 1, wherein the whiskers are zinc oxide whiskers.
 4. The multilayered golf ball according to claim 1, wherein the inner cover layer is formed from a highly neutralized acid polymer resin or a metal cation based low acid ionomer resin.
 5. The multilayered golf ball according to claim 1, wherein the outer cover layer is formed from a metal cation based low acid ionomer resin.
 6. The multilayered golf ball according to claim 1, wherein the ball core has a coefficient of restitution between 0.65 and 0.85.
 7. A method for manufacturing a multilayered golf ball having inside whiskers, comprising: forming a ball core; forming an inner cover layer to cover the ball core, wherein the inner cover layer has a flexural modulus between 20 MPa and 400 MPa, the inner cover layer has a three-dimensional network structure that is formed by the whiskers, and the whiskers are in an amount between 1 wt % and 5 wt % of the total weight of the inner cover layer; and forming an outer cover layer to cover the inner cover layer, wherein the outer cover layer has a flexural modulus between 20 MPa and 600 MPa.
 8. The method according to claim 7, wherein the whiskers are in an amount between 2.5 wt % and 3 wt % of the total weight of the inner cover layer.
 9. The method according to claim 7, wherein the whiskers are zinc oxide whiskers.
 10. The method according to claim 7, wherein the step of forming the inner cover layer includes: mixing the whiskers and one molding resin in a weight ratio of 1:9 to form a first resin composition; granulating the first resin composition to form masterbatches; mixing the masterbatches and another molding resin in a weight ratio of 3:7 to form a second resin composition; and using the second resin composition as a raw material for injection molding.
 11. The method according to claim 10, wherein each of the one molding resin and the another molding resin is a highly neutralized acid polymer resin or a metal cation based low acid ionomer resin.
 12. The method according to claim 7, wherein the outer cover layer is formed from a metal cation based low acid ionomer resin.
 13. The method according to claim 7, wherein the ball core has a coefficient of restitution between 0.65 and 0.85. 